74 



Key to the Indo-Australian species. 



A. Maxillary teeth gradually enlarged posteriorly. 



I. Internasals much narrowed in front ; nostrils 

 directed upwards and outwards; scales in 19 



rows 1. T. piscalor p. 75. 



II. Internasals broadly truncate in front ; nostrils 

 lateral. 



a. Scales in 15 rows. 



\ Upper labials 8 usually. 

 X Subcaudals less than 60. 



1. Scales strongly keeled; three or four 

 postoculars 2. 



2. Scales feebly keeled ; two postoculars. 3 



3. Scales feebly keeled; three post- 

 oculars. 

 aa. Internasals shorter than praefron- 



tals; frontal longer than its dis- 

 tance from the tip of the snout. 

 bb. Internasals as long as praefrontals; 

 frontal as long as its distance from 



the tip of the snout 



XX Subcaudals usually more than 60. 



T. picturatus p. 76. 

 T. tru7icatus p. 77. 



4. T. cdchicus p. 78. 



5. T. novae-guineac p. 78. 



l.Ventrals 137 — 141 



subcaudals 



6. 



T. sarasinoruDi p. 79. 

 T. mairi p. 79. 



8. T. montanus p. 80. 



65 — 75; I prae- and 3 postoculars. 



2. Ventrals 137 — 170; subcaudals 

 51 — no; 2 prae- and 3 postoculars. 



3. Ventrals 164; subcaudals 76; 2 prae- 

 and 3 postoculars; tail with longitu- 

 dinal dark bands 



4. Ventrals 162 — 165; subcaudals 72 ; 2 

 prae- and 3 postoculars; posterior part 



of body with dark longitudinal lines. 9. T. elongatus p. 80, 

 tt Upper labials 9. 



aa. Ventrals 162; belly white, with 6 longi- 

 tudinal rows of black dots 



^3, Ventrals 172 — 180; belly white ante- 

 riorly, speckled and powdered with 

 blackish in the middle, black poste- 

 riorly 



/^.Scales in 17 rows. 



I. Three labials entering the eye; ventrals 

 141 — 158; subcaudals 50 — 85 12 



10. T. puiictiventris p. 81. 



II. T. halinahericus p. 82. 



T. doriac p. 82. 



